The project is designed to develop new instrumentation and methods and to improve existing instrumentation and techniques for the characterization of biological macromolecules and for study of their interactions.. Analytical ultracentrifugation, the techniques ancillary to it, and methods of data analysis using mathematical modeling appropriate for these techniques are the major areas of interest. Studies on the application of mathematical modeling to problems of ultracentrifugal analysis have continued. The applications of these studies are described in the project report 10184-06. Major progress has been made in the development of data acquisition systems. Two new data acquisition systems for the analytical ultracentrifuge have been developed. The Macintosh II analog-to-digital acquisition system has also been completed and a direct digital acquisition system using the Macintosh is nearly completed. New methods of performing experiments and analyzing data have been developed and work is continuing in this area.